APPARATUS FOR BRACING VERTEBRAE
An apparatus for bracing a plurality of vertebrae of the human spine has at least two pedicle screws, each having an annular head with an opening therewithin and including a slot therewithin. Each slot extends into the corresponding opening and includes internal threaded portions. A securing screw to be screwed in each slot is provided. A relatively stiff threaded rod is also provided and is to be inserted into the opening in the head of each of the pedicle screws and to be secured by the securing screws. Adjusting nuts are screwed on the rod and at least one cooperates with each head.
1 . A pedicle attachment assembly comprising:
an anchoring element having a head and a fastening portion to secure said anchoring element to a bone;
a cage having a longitudinal axis extending between a first end and a second end, a seat for said head, said seat being adjacent said first end, an aperture at said first end and from which said fastening portion extends exterior to said cage when said head is in said seat, an opening for receiving a rod such that a rod received therein extends transversely to said longitudinal axis and is positioned above said head, said opening having a surface facing said second end of said cage, whereby a rod arranged in said opening is spaced from said surface; and
a securing member engageable with said cage above said rod and being movable along said longitudinal axis toward said first end.
2 . The pedicle attachment assembly in claim 1 , wherein said cage may be pivoted with respect to said anchoring element until said securing member generates sufficient locking forces to lock said cage with respect to said head.
3 . The pedicle attachment assembly in claim 2 further including a rod disposed in said opening and extending transversely to said longitudinal axis of said cage, and wherein said rod directly engages said head of said anchoring element.
4 . The pedicle attachment assembly in claim 1 , wherein said fastening portion is threaded.
5 . The pedicle attachment assembly in claim 1 , wherein said cage includes a threaded portion arranged interiorly on said cage and said securing member includes threads cooperable with said threaded portion.
6 . The pedicle attachment assembly as set forth in claim 1 further including a rod disposed in said opening and extending transversely to said longitudinal axis of said cage.
7 . The pedicle attachment assembly in claim 6 , wherein said opening in said cage is in the form of channels open to said second end such that said cage has a U-shaped profile.
8 . The pedicle attachment assembly in claim 6 , wherein said securing member directly engages said rod and said rod directly engages said head of said anchoring element.
9 . The pedicle attachment assembly in claim 1 further including a rod disposed in said opening and extending transversely to said longitudinal axis of said cage, and wherein said head is at least partially spherical, said fastening portion is a threaded portion, and said cage may be pivoted with respect to said anchoring element until said securing member generates a sufficient locking force to lock said cage with respect to said head.
10 . The pedicle attachment assembly in claim 9 , wherein said opening in said cage is in the form of channels open to said second end such that said cage has a U-shaped profile.
11 . The pedicle attachment assembly in claim 9 , wherein said seat is at least partially spherical.
12 . The pedicle attachment assembly in claim 9 , wherein said securing member includes threads and said cage includes a threaded portion arranged interiorly on said cage.
13 . The pedicle attachment assembly in claim 9 , wherein said rod directly engages said head of said anchoring element.